FIG. 1 depicts a portion of a conventional magnetic transducer 10, such as a conventional read transducer or other device. The conventional transducer 10 resides on a conventional substrate 11, such as an AlTiC substrate. The conventional transducer 10 includes a conventional bottom shield 12, conventional seed layers 14 and 16, conventional antiferromagnetic (AFM) layer 18, conventional sensor 20, and conventional top shield 30. The conventional bottom seed layer 14 typically includes Ta or Cu and adjoins, or shares an interface with, the conventional shield 12. The thickness of the Ta layer 14 is typically twenty through fifty Angstroms. The conventional seed layer 16 typically includes Ru, NiFeCr, NiFe, or CoFe and adjoins the conventional nonmagnetic seed layer 14. Thus, the conventional seed layers 14 and 16 may be viewed as forming a bi-layer seed layer including, for example, Ta/Ru, Ta/NiFe, Ta/NiFeCr, or Ta/CoFe layers. The conventional shields 12 and 30 typically include NiFe and are formed by plating.
The conventional sensor 20 typically includes a pinned layer that is usually a synthetic antiferromagnetic (SAF) layer 22, a nonmagnetic layer 24, a free layer 26, and a capping layer 28. The conventional SAF layer 22 typically includes two ferromagnetic layers (not separately shown) separated by a nonmagnetic spacer layer (not shown). The ferromagnetic layers are generally antiferromagnetically coupled. The magnetization(s) of the conventional SAF layer 22 are pinned by the conventional AFM layer 18. More specifically, the first ferromagnetic layer adjoining the conventional AFM layer 18 has its magnetization pinned by the conventional AFM, for example via exchange interaction. The remaining ferromagnetic layer has its magnetization pinned because it is strongly magnetically coupled with the first ferromagnetic layer. The conventional nonmagnetic layer 24 may be a barrier layer or a conductive spacer layer. If a barrier layer 24 is used, then the sensor 20 is a tunneling magnetoresistive (TMR) sensor. If a conductive spacer layer 24 is used, then the sensor 20 is a spin valve or for current perpendicular to the plane giant magnetoresistance sensor.
Although the conventional transducer 10 and conventional sensor 20 may function, issues may arise in higher density magnetic recording applications. The areal storage density in a hard disk drive using the conventional transducer 10 increases dramatically every year. In order to maintain the magnetic properties of the transducer 10, such as high exchange bias and reduced dispersion, the shield-to-shield distance, h1, is desired to be decreased. However, reduction of the thickness of various layers, such as the conventional AFM layer 18 or conventional seed layers 14 and 16 adversely affects performance of these layers. For example, reducing the thickness of the conventional AFM layer 18 may reduce its ability to pin the magnetizations of the conventional SAF 22. This may allow the magnetizations of the conventional SAF 22 to change direction, at least to a degree. Consequently performance of the conventional transducer 10 is adversely affected. Similarly, a reduction in the thicknesses of the conventional seed layers 14 and 16 may reduce the quality of the conventional AFM layer 18. As a result, the ability of the conventional AFM layer 18 to pin the magnetization of the conventional SAF 22 is again diminished. Consequently, performance of the conventional magnetic transducer 10 may again be adversely impacted.
Accordingly, what is needed is a system and method for providing a transducer having a reduced shield-to-shield spacing that may be usable for higher density recording.